UAC Dialog Creation

For clients, if the stack is configured to maintain dialogs, the stack creates a dialog for an incoming response to a dialog creating request. Dialog creating requests are either INVITE or SUBSCRIBE. For SUBSCRIBE requests, a corresponding NOTIFY request also creates a dialog. The stack can create multiple dialogs for a single request if the application specifies multiple dialogs by using the sip_sendmsg() function.

For servers, if the stack is configured to maintain dialogs, the stack creates a dialog when the application sends a response to the dialog creating request. The stack also creates a dialog when it sends a NOTIFY request in response to a SUBSCRIBE request.